Clinical stage IA non-small cell lung cancer with occult pathologic N1 and N2 disease after segmentectomy: does a completion lobectomy justify?

OBJECTIVES When final pathology shows pathologic N1 or N2 disease after a pulmonary segmentectomy for early stage non-small cell lung cancer (NSCLC), completion of lobectomy could be considered and recommended as an option for treatment. We explored outcomes after segmentectomy for clinical stage IA NSCLC with occult pN1 or pN2 disease. METHODS We identified clinical stage IA NSCLC undergoing segmentectomy or lobectomy from the National Cancer Database (NCDB) between 2010 and 2020. We categorized patients by pathologic N diseases (pN0/pN1/pN2). We compared segmentectomy to lobectomy adjusting for patient and clinical characteristics. We explored survival using time-varied Cox regression, 30-day, 90-day mortality and unplanned 30-day readmission using logistic regression, and length of stay using Poisson regression. RESULTS Of 123 085 clinical IA NSCLC, 7.9% underwent segmentectomy. Pathology showed 2.8% pN1 and 1.9% pN2 after segmentectomy, and 6.5% pN1 and 3.7% pN2 after lobectomy. For pN1, segmentectomy conferred 33% better survival within 2 years (aHR = 0.67, P = 0.03), but similar survival after 2 years (aHR = 1.06, P = 0.7). For pN2, segmentectomy had similar survival with lobectomy (aHR = 0.96, P = 0.7). For all clinical IA NSCLC, segmentectomy was associated with lower 30-day mortality (aOR = 0.55, P < 0.001), 90-day mortality (aOR = 0.57, P < 0.001), readmission (aOR = 0.86, P = 0.01) and shorter length of stay (aRR = 0.76, P < 0.001) than lobectomy. CONCLUSIONS Outcomes after segmentectomy for clinical stage IA NSCLC may be associated with better short-term mortality, readmission rate and length of stay. Survival with occult pN1 and pN2 after segmentectomy is at least equivalent to lobectomy in completely resected clinical stage IA patients. A completion lobectomy may not be needed after pN1 and N2 findings after the permanent pathology was released.